For the cleaning of streets and other surfaces, e.g. the floors of industrial plants, it has been proposed heretofore, by myself and others, to train jets of high-pressure water upon the surface and to collect the reflected dirty water in a trough. The dirty water is generally filtered and recirculated to the aforementioned jets.
The jets are generally operated at extremely high pressure, e.g. up to several hundred Bars.
To pick up the dirty water in the conventional processes, the aforementioned troughs are used, the water entering these troughs primarily by reflection from the surface. In practice it has been found that this technique does not avoid water losses. To reduce the water losses, it has been proposed to substitute for the aforementioned collection troughs, suction devices and associated suction funnels which can be connected to the dirty water recovery duct. In such systems, the pressurized-water nozzles generally train the respective water streams beneath the suction funnel.
In practical embodiments of such apparatus, the pressurized-water nozzles are disposed, with respect to the direction of travel of the vehicle, behind the suction funnel while ahead of the suction funnel there is provided means for generating an air curtain. The compressed air nozzles which serve for this purpose produce a barrier for wayward reflected water and for the dirty water.
In another construction, the pressurized-water nozzles can be oriented ahead of the suction funnel, usually beneath a covering tunnel. Even with the latter construction, however, and in spite of the pressurized-air curtain or lock and the covering tunnel, the water losses are found to be relatively high and the suction effect for intensive cleaning is not entirely satisfactory.